When he learns his days are numbered old count Hervé de Kéraudren decides to hide in a secret alcove and to die there, just to annoy his heirs. As a result of his body not being found the latter will have to wait for five years until they can inherit the count's money. Very upsetting indeed, all the more as they are required to keep up the Kéraudren estate in the meantime. To collect money, nephews and nieces organize a Son et Lumière show at the manor while busily looking for the missing corpse. But, unexpectedly, they get killed in turns. Murders or accidents? Jean-Marie, his fiancée Micheline and his cousin Edwige investigate and finally succeed in exposing the culprit. And, the count's body being found by chance, all goes back to normal.。改编自玛丽·斯图尔特英国儿童文学小说,玛丽被送到乡下阿姨家过暑假,在一只小黑猫的带领下,她进入森林找到一束紫色魔法花,打扫院落时她用沾有花粉的手碰了扫帚,扫帚突然腾空而起,竟然把她送到森林深处的魔法学校,在这里她学习各种神奇有趣的魔法,但玛丽也发现了这所学校不可告人的秘密。。